"Cannot synchronize host" error after mgmt network change

[zenking]

Hi. I have ESXi and vCenter 6.7 with standard vSwitches. I'm having what I suspect is a certificate issue since making the changes below.

I've added a vswitch with new 10g nics to each of my ESXi hosts. The new nics are connected to new switches for better redundancy in our hosted datacenter. I set up new port groups and moved my VMs to the switch a couple of weeks ago and have had no problems.

Today, I added a vmkernel and enabled the management service on it. I put the host in maint mode, removed from the cluster and readded using the new IP from the new vmkernel. That all seemed to work, but I see these problems:

- I can't connect directly to the host using the new IP address. I can connect with the old IP, but I'm getting the cert warning.

- The vcenter console shows "Cannot synchronize host <ip address>"

Is there an easy fix for this? Thanks. I'm waiting to change the other hosts in case there's a step I need to perform along the way.

ETA: Forgot to say that I have not registered the new IP with dns yet, but I joined using the IP and I'm using the IP to connect to the web client.

[zenking]

After registering the new IP in DNS and restarting the mgmt network on the host, the sync error has gone away. Proceeding with the other hosts.